All-terrain vehicle

ABSTRACT

Disclosed herein is an all-terrain vehicle including a track suspension system affording both transverse and lateral resiliently flexible support to an endless track and a releasably locked and pivotally mounted rear bogie wheel assembly which, when pivoted from its normal operating position, affords assembly of or removal of the endless track relative to the sprocket and bogie wheels.

United States Patent 1191 Jespersen Feb. 5, 1974 [54] ALL-TERRAINVEHICLE 3,362,492 1/1968 Hansen 305 27 x 1,539,582 5/1925 Landr 305/27175] 1,856,068 5/1932 Christi e 305/22 x Nebr' 3,017,942 1/1962 Gamaunt180/92 R [73] Assignee: Outboard Marine Corporation,

waukegan Primary Examiner-Richard J. Johnson [22] Filed: Nov. 27, 1970Attorney, Agent, or FirmMichae1, Best & Friedrich [21] Appl. No.: 93,474

Related US. Application Data 57] ABSTRACT [62] Division of Ser. No.857,494, Sept. 12, 1969,

abandmed- Disclosed herein is an all-terrain vehicle including a tracksuspension system affording 130th transverse and [52] US. Cl. 305/22,305/27 lateral resiliently fl support to an endless track [51] Int. ClB62d 55/16 d a releasably l k and pivctany mounted real- [58] Fleld ofSearch 305/27, 25, 22, 35 EB; bogie wheel assembly which, when pivotedfrom its 180/92 normal operating position, affords assembly of orremoval of the endless track relative to the sprocket and [5 6]References Cited bogie wheels UNITED STATES PATENTS Marier 305/27 7Claims, 9 Drawing Figures PAIENIED 51974 3. 790.230

SHEET 1 or 4 PAIENIEU FEB 51924 SHEET 2 [IF 4 PAIENIED SW4 3. 790.230

saw a nr 4 36/ 25/ 3&7 529/ ALL-TERRAIN VEHICLE RELATED CASE Thisapplication is a division of my co-pending application Ser. No. 857,494,filed Sept. 12, 1969, and now abandoned.

BACKGROUND OF THE INVENTION The invention relates to so-calledall-terrain vehicles which have a high capability for travel overdifficult and rough ground contours, conditions and textures. Theinvention also relates to track vehicles and especially to vehiclesadapted to travel over snow and mud.

The invention further relates to sprocket constructions and to tracksuspensions. In connection with sprocket constructions, reference ismade to U. S. application Ser. No. 685,214, now US. Pat. No. 3,542,623.

SUMMARY OF THE INVENTION The invention provides a superior all-terrainvehicle capable of reliable performance over a wide range of groundconditions. One of the features of the invention resides in tracksuspension group whereby both lateral and longitudinal resilient supportis provided for an endless belt or track. In this regard, the tracksuspension assembly, at each side of the vehicle body, incudes aplurality of paired inner and outer bogie wheels which are located ingenerally adjacent transverse relation to each other and which aresupported for vertical movement independently of each other, whereby toafford resilient transverse flexible support for the endless belts.

In addition to the foregoing, each track assembly includes a rear bogiewheel assembly which is pivotally mounted to the supporting frame so asto afford displacement of the rear bogie wheels to a positionconveniently affording placement of the endless track about the drivesprocket and around the bogie wheel assemblies. Upon such assembly, therear bogie wheel assembly is swung back into its normal operatingposition and releasably locked in place to prevent loss of the endlesstrack from the supsension assembly.

Another of the aspects of the rear bogie wheel construction is thearrangement for maintaining track tension, notwithstanding any stretchor elongation which may occur to the track.

Still another feature of the rear bogie wheel assembly is thearrangement of an elastomeric mount to afford limited resilient movementof the rear bogie wheels from their normal operating position.

Still another feature of the invention resides in the generalarrangement of the various bogie wheels to the frame of the tracksuspension group and thearrangement for connection of the tracksuspension group to the body.

Still another feature of the invention resides in the relationshipbetween the bogie wheel sprocket diameter and the lugs and the inside ofthe endless track. More specifically in this regard, the lugs and thediscs are dimensioned such that, at least two teeth are always engagedwithin each bogie wheel during movement of the track, thereby reliablyassuring retention of the track in proper aligned relation to theassociated track suspension system.

In general, the principal object of the invention is to provide asuperior all-terrain vehicle which is economical to manufacture andassemble, which can be readily repaired, and which is entirely reliablein operation.

Other objects and advantages of the invention will become known byreference to the following description and accompanying drawings inwhich:

DRAWINGS FIG. 1 is a perspective view of a track vehicle embodyingvarious of the features of the invention.

FIG. 2 is an exploded elevational view, partially broken away insection, of the power generating and transmission group, the body, andthe track suspension group of the vehicle shown in FIG. 1.

FIG. 3 is a front elevational view, partially in section, of the frontbogie wheel assemblies incorporated in the track suspension group of thevehicle shown in FIG. 1.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3.

FIG. 5 is a sectional view taken along line 5--5 of FIG. 4.

FIG. 6 is a plan view, partially in section, of the rear bogie wheelassembly of the track suspension group.

FIG. 7 is an end elevational view, partially in section, of the rearbogie wheel assembly shown in FIG. 6.

FIG. 8 is a sectional view taken along line 88 of FIG. 6.

FIG. 9 is a fragmentary perspective view of a portion of the trackemployed on the vehicle shown in FIG. 1.

GENERAL DESCRIPTION Shown in the drawings and especially in FIG. 1, isan all-terrain vehicle 11 built in accordance with the invention. Thevehicle is desirably constructed by assembling three main assemblies ormodules (See FIG. 2), namely, a body 13, a power generating andtransmission group 15, and a track suspension group 17 which includes,on each side of the vehicle, a track suspension system 21. In additionto the foregoing, full construction of the vehicle is generallycompleted by assembling a motor hood 23 over the power group and byconnecting a pair of sprockets 25 to the power group and by training anendless longitudinal and transversely flexible track 27 around thesprocket 25 and track suspension system 21 at each side of the vehicle11.

The track suspension group 17 can be assembled independently of the body13 and the power generating and transmission group 15 and subsequentlyassembled to the body 13 independently of assembly of the powergenerating and transmission group 15 to the body 13. In accordance withthe invention, the track suspension group 17 includes a frame or support341 having a plurality of structural cross members which arerespectively and individually located in the respective downwardly openchannels 45 formed in the bottom of the body. While various arrangementsare possible, in the disclosed construction (See the lower portion ofFIG. 2), the frame 341 includes a forward cross member 343 and anintermediate cross member 345 and a rearward cross member 347.

The cross members 343, 345 and 347 are integrated into the frame 341 bylongitudinal beams. While various arrangements can be employed, in thedisclosed construction, two beams 349 are employed, which beams arerespectively and suitably connected to the opposite ends of the crossmembers 343, 345 and 347.

If desired, the beams could be connected to the cross members inwardlyof the ends thereof.

The track suspension group 17 is connected to the body 13 to maintainthe body watertight and so as to locate the cross members 343, 345 and347 in the downwardly open channels 45 by suitable means which arewelded or otherwise fixed to the cross members and which are adapted tospan the ends of the channels 45 and to contact and to be fixed to theexterior surface of the side margins around the channel ends.

Carried along each side of the track assembly frame 341 and under theadjacent deck wall 49 is a track suspension system. Each of thesuspension systems includes inner and outer front bogie wheels 357 and359 (See FIG. 3), intermediate inner and outer bogie wheel assemblies363 (See bottom portion of FIG. 2), a rear bogie wheel assembly 367 andinner and outer rearward idler bogie wheels 371 and 373 (See FIG. 6). Aseach suspension system is identical, only one will be described.

Located at the front end of the track suspension frame 341 are the innerand outer first or front rotatable bogie wheels'357 and 359 which areseparately supported in transversely adjacent and generally axiallyaligned relation to each other for rotational movement about theirrespective centers and for limited pivotal movement about the forwardcross member 343. More particularly, the inner and outer bogie wheels357 and 359 are generally of the same construction and, as shown best inFIG. 5, comprise a pair of transversely spaced discs 381 having alaterally outwardly extending thin peripheral lip 383. The discs 381 arekeyed or otherwise fixed to a shaft having a central bearing 387received in a sleeve 389 which includes, at each end, a counterborereceiving a seal member 393 which prevents entry of dirt or moistureinto the bearing 387. In addition, each of the discs 38] is providedwith a counterbored inwardly extending hub portion 395 which receivesthe end portions of the sleeve 389 to further assist in excluding dirtor moisture.

While various arrangements can be employed, in the disclosedconstruction, in order to permit lessening of shock upon contact of thetrack 27 with large obstacles and to ease passage of the vehicle overlarge obstacles, means are provided to support the front bogie wheelswhile, at the same time, affording resilient rearward swinging movement,thereby decreasing the angle of the upwardly and forwardly extendingtrack to the ground.

As the arrangement for supporting each of the inner and outer frontbogie wheels 357 and 359 is essentially the same, only the arrangementfor supporting the outer front bogie wheel 359 will be described.

More particularly in the disclosed construction, as shown in FIGS. 3, 4and 5, the outer front bogie wheel 359 is mounted for resilient swingingmovement about the axis of the front cross member 343 by means includinga generally vertically extending support bar 399 and a rubber torsionbushing assembly 401. Still more particularly, the torsion bushingassembly incudes an inner sleeve 403 which is telescoped onto the frontcross member 343 into proper position and are suitably spaced and fixedthereto. The outer periphery of the sleeve is cylindrical and has bondedthereto a ring or annulus 405 of rubber or other rubber-like elastomericmaterial. Bonded to the outer cylindrical surface of the ring 405 is acylindrical metallic jacket 407 having a pair of diametrically radiallyoutwardly extending ears 409. The bushing assembly is received in anupwardly open cradle 411 which is welded or otherwise suitably connectedto the upper end of the support bar 399 and which has a pair ofdiametrically extending tabs 413 which mate with the ears 409 and aresuitably connected thereto, as by bolts or the like. At its lower end,the support bar 399 is welded to the bogie wheel sleeve 389.

The extent of the resilient pivotal movement permitted to the frontbogie wheels 357 and 359 is determined by the torsional resistance ofthe rubber ring 405.

Intermediate its ends, the track suspension system further includesintermediate inner and outer bogie wheel assemblies 363 each havingrotatably mounted second and third bogie wheels 419 which are generallyof the same construction as the front bogie wheels and which arearranged and supported such that the axes of the inner second and thirdbogie wheels are generally respectively laterally aligned with respectto the axes of the outer second and third bogie wheels.

As in the case of the front bogie wheels, the intermediate inner andouter bogie wheel assemblies 363 are separately supported. Each of theintermediate inner and outer bogie wheel assemblies 363 includes meansfor supporting the bogie wheels for resilient up and down movement andfor pivotal movement about a transverse axis located intermediate thesecond and third bogie wheels. The construction of the intermediateinner and outer assemblies is generally the same.

To achieve the foregoing support, the sleeves of the outer bogie wheelsare suitably connected, as by clamps 423, to the ends of a leaf spring425 which, intermediate the ends thereof, is suitably fixed, as by aclamp 427, to the web 429 of an inverted U-shaped bracket 431 havingupwardly extending legs supporting a fixed pivot 433. In turn, the fixedpivot 433 is received in a bushing or sleeve 435 which is locatedbetween the bracket legs and fixed to the lower end of a post 437depending fixedly from the intermediate cross member 345. A

While separate pivots have been provided for each of the intermediateinner and outer bogie wheels assemblies 363, a single pivot member couldbe employed to support both inner and outer bogie wheel assemblies andstill provide the same functional result. Thus, the intermediate bogiewheel assemblies 363 have independent pivotal movement about an axisextending transversely between the second and third bogie wheels and, inaddition, each of the bogie wheels is supported so as to affordresilient up and down movement relative to the other bogie wheel of eachassembly, as well as rotative movement about its own axis.

Supported on the rear cross member 347 is the rear bogie wheel assembly367 which includes fourth and fifth inner rotatable bogie wheels 445 andfourth and fifth outer rotatable bogie wheels 445 which are respectivelylocated in transversely adjacent and axially aligned relation to thefourth and fifth inner bogie wheels. Each of the inner and outer fourthand fifth bogie wheels 445 is of like construction to the front bogiewheels. The fourth and fifth outer bogie wheels are integrated into anouter bogie wheel sub-assembly 447 by a strut or rocker bar 449 which iswelded or otherwise fixed at its ends to the sleeves of the fourth andfifth outer bogie wheels. A similar rocker bar 451 is fixed so as tointegrate the fourth and fifth inner bogie wheels into an innersub-assembly 453.

In order to provide for independent movement of the inner and outerbogie wheel sub-assemblies 447 and 453 so as to provide bothlongitudinal and transverse flexiblity, the inner and outer bogie wheelsubassemblies each include mounting means affording pivotal movementabout aligned axes intermediate the foruth and fifth bogie wheels.

While various arrangements can be employed to separately afford pivotalmovement for the inner and outer bogie wheel sub-assemblies 447 and 453,the arrangement for both bogie wheel sub-assemblies is the same. Onlythe arrangement at the outer bogie wheel assembly, as shown in FIG. 6,will be described in detail.

More particularly, the outer bogie wheel subassembly 447 has fixedthereto, as by welding or otherwise, a bushing or sleeve 457 which islocated centrally of the associated bar 449 and which receives a pivotpin 459. In turn, the pivot pin 459 is fixed by welding or otherwise tothe spaced downwardly extending legs 461 of a U-shaped bracket orconnecting member 463 which straddles the sleeve 457 and which has aconnecting web 465 located above the bar 449.

Also forming a part of the connecting bracket 463 is a right angleflange 467 which is welded or otherwise suitably fixed to the web 465and which serves as a point of assembly to a cross bar or member 469having welded, or otherwise suitably fixed to each end, a connectingplate or flange 471 which are respectively fixed, as by bolts 473, tothe connecting brackets 463 associated with each of the inner and outerbogie wheel sub-assemblies 447 and 453.

Connected to the under-surface of the cross bar 469 for support thereofis a hollow tube 475 which is of rectangular cross-section and istelescoped on the rear end of a generally horizontal extending rear endportion 477 of an arm 479 which also includes a somewhat enlargedupwardly bent portion 481 connected to the rear cross member 347. Meansare provided to maintain proper tension in the track. Variousarrangements, including screw means can be employed. In the specificallydisclosed construction, one or more shims 483 are located in telescopicrelation on the rear end portion 477 of the arm 479 between thetelescoping tube 475 and the upwardly inclined arm portion 481. As shownin FIG. 6, a cotter pin 485 can be employed adjacent to the rearward endof the rear end portion 477 to prevent disconnection of the telescopingtube 475 and the rearward end portion 477 of the arm 479.

In order to permit the endless tracks 27 to be slipped over theassociated bogie wheels and sprockets, each raear bogie wheel assembly367 is fixed to the rear cross member 347 so as to afford pivotalmovement therebetween. While various means can be utilized to providesuch pivotal construction, in the disclosed construction, the upper endof each arm 479 has fixed thereto, See FIG. 7, a bushing 491 whichreceives a pivot pin 493 extending between a pair of spaced parallelplates or brackets 495 suitably fixed, as by welding or otherwise, tothe rear cross member 347 in adjacent outward relation to the opposedsides of the associated arm 479.

Means are provided to locate the arm 479 in proper angular relation tothe rear cross member 347 and to releasably retain the arm 479 in suchangular relation to the rear cross member 347. While variousarrangements can be employed, in the disclosed construction, such meansincludes, at the rearward end of the plates 495, upper and lower bolts497 and 499 which extend between the parallel plates above and below thearm 479 so as to confine the arm in proper angular relationship to thecross member 347. However, in order to swing the arm 479 downwardly,i.e., counterclockwise, as shown in FIG. 7, about the pivotal engagementon the pin 493, and to thereby facilitate slipping of the associatedtrack over the sprocket and bogie wheels, the lower bolt 499 isremovable.

Means are provided to establish a normal position for each of the rearbogie wheel sub-assemblies 447 and 453, to independently permitresilient pivotal movement of each subassembly relative to said normalposition and to limit pivotal movement of each subassembly from thenormal operating position. As the arrangement provided for each of theinner and outer bogie wheel assemblies 447 and 453 is generallyidentical, only the construction associated with the outer bogie wheelsubassembly 447 will be described.

While various arrangements can be employed to establish a normaloperating position and to afford resilient pivotal movement relative tosaid normal position, in the disclosed construction, an elastomeric orrubber mount or spring 503 is connected between the connecting flange471 of the bogie wheel assembly cross bar 469 and the outer sub-assemblyfore and aft bar 449. More particularly, the resilient mount 503comprises a cylindrical body of rubber or other like material havingimbeded therein separate threaded studs which extend from the oppositeends of the cylindrical body. One of said studs extends through and isbolted at 505 to a forward extension 507 of the connecting flange 471 atthe adjacent end of the rear bogie wheel cross bar 469. The other studextends through and is: bolted at 509 to an upright bracket 511 which iswelded or otherwise fixed to the outer fore and aft beam 449 of theouter subassembly 447.

Accordingly, each sub-assembly 447 and 453 tends to assume a normalposition in which the rubber mount 503 is not under stress. However, therubber mount 503 will deform in shear to offer resilient pivotalmovement away from the normal position and to accommodate track flexurein conformance with ground conditions.

While other means can be employed, pivotal move ment from the normalposition in the counterclockwise direction, as shown in FIG. 7, isessentially prevented by engagement of the rear under-surface of the web465 with the bogie sub-assembly fore and aft beam 449. Pivotal bogiesub-assembly movement in the clockwise direction from the neutralposition is limited by engagemet of the sub-assembly fore and aft beam449 with (See FIG. 6) a bent ear or tab 515 at the forward extremity ofthe connector flange extension 507 to which the rubber mount 503 isconnected. Thus, each of the rear bogie wheel assemblies 367 includesinner and outer bogie wheel sub-assemblies 447 and 453 which provideflexible support to the track in both the longitudinal and transversedirections. I

Also forming a part of each track suspension system are a pair of upperrearward inner and outer idler bogie wheels 371 and 373 which areconstructed in generally the same manner as the front bogie wheels. Eachof the rearward idler bogie wheels are respectively fixed (as shown bestin FIGS. 6 and 7) by separate arms 521 which, at one end, are welded orotherwise suitably secured to the rear cross member 347 and, at theother end, are suitably fixed to the associated bogie wheels as byemployment of respective clamps 523 encircling the respective bogiewheel sleeves.

It should be noted that, generally speaking, all of the inner bogiewheels are generally longitudinally aligned and that all of the outerbogie wheels are similarly longitudinally aligned.

The tracks 27 are of endless construction of rubber or other similarmaterial and include, on the outer surface, longitudinally spacedtransverse treads 531 (See FIGS. 3 and 9), as well as rows oftransversely spaced studs or buttons 532 which are located intermediatethe transverse treads 531. In addition, the outer surface of the tracks27 is provided along both longitudinal edges with a rib or margin 533which is raised to an extent less than the height of the treads 531 andthe studs 532. On its inner surface, each track 27 includes a pair oflongitudinally extending parallel series of lugs 535 which are engagedby the sprocket teeth 325 and extend within the spaced discs 381 of thebogie wheels.

It is especially noted that the studs 532 assist the margins 533 inpreventing lateral slippage of the tracks in snow or mud or the like. Inaddition, the studs 532 are transversely located so as to be inlongitudinal alignment with the outer edges or rims 383 of the bogiewheels. Thus, the studs 532 are located in laterally outwardly adjacentrelation to the lugs 535 but on the opposite side of the track. Locationof the studs 532 in alignment with the rims 383 of the bogie wheel discs381 provides a smoother, quieter ride as the studs 532 prevent anytendency toward track flexure which might otherwise occur as aconsequence of travel of the bogie wheels relative to flat ground.

In general, the tracks 27 are generally unbroken to obtain the greatestpossible load supporting surface and are flexible in both thelongitudinal and transverse direction. Such flexibility is illustratedin FIG. 3 wherein the right side of the track is shown passing over anobject 537 which does not extend for the full width of the track.

In addition, it is noted that the diameter of the bogie wheel discs 381is so related to the size or dimensions of the lugs 535 such that, atleast portions of two lugs are transversely retained within he paralleldiscs 38] of each bogie wheel at all times, thereby assuring propermaintenance of the track on the track suspension system.

Various of the features of the invention are set forth in the followingclaims.

What is claimed is:

l. A track suspension comprising a support having, on each side thereof,an intermediate portion, front inner and outer bogie wheels, meansseparately mounting each of said front inner and outer bogie wheels fromsaid support forwardly of said intermediate portion in adjacently spacedrelation to each other transversely of the direction of intended travelfor resilient pivotal movement about an axis transverse to the directionof intended travel and spaced from the center of said front inner andouter bogie wheels, second inner and outer bogie wheels, third inner andouter bogie and for independent vertical movement, means includinganother common member extending from said intermediate support portionfor mounting said second and third outer bogie wheels in spaced relationto each other in the direction of intended travel and with said secondand third outer bogie wheels being respectively located in adjacentlyspaced relation to said second and third inner bogie wheels transverselyof the direction of intended travel and for independent verticalmovement of said second and third outer bogie wheels relative to eachother and to said second and third inner bogie wheels, fourth inner andouter bogie wheels, fifth inner and outer bogie wheels, and meansmounting said fourth and fifth inner and outer bogie wheels from saidsupport rearwardly of said intermediate portion with said fourth innerand outer bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel and with said fifthinner and outer bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel and for common pivotalmovement of said outer fourth and fifth bogie wheels and common pivotalmovement of said inner fourth and fifth bogie wheels independently ofsaid outer fourth and fifth bogie wheels and about an axis spaced fromsaid support.

2. A track suspension comprising a support, inner and outer front bogiewheels in adjacently spaced relation to each other transversely of thedirection of intended travel, means separately connecting each of saidinner and outer front bogie wheels to said support for limited resilientpivotal movement about an axis transverse to the direction of intendedtravel and spaced from the center of said inner and outer front bogiewheels, second inner and outer bogie wheels in adjacently spacedrelation to each other transversely of the direction of intended travel,third inner and outer bogie wheels in adjacently spaced relation to eachother transversely of the direction of intended travel, means includingan outer leaf spring pivotally connected intermediate the ends thereofto said support and respectively connected at opposite ends to saidsecond and third outer bogie wheels and an inner leaf spring pivotallyconnected intermediate the ends thereof to said support and respectivelyconnected at the opposite ends thereof to said second and third innerbogie wheels for affording independent vertical movement of each of saidsecond and third outer and inner bogie wheels, fourth inner and outerbogie wheels in adjacently spaced relation to each other transversely ofthe direction of intended travel, fifth inner and outer bogie wheels inadjacently spaced relation to each other transversely of the directionof intended travel, an outer rocker bar connected to said outer fourthand fifth bogie wheels, an inner rocker bar connected to said innerfourth and fifth bogie wheels, and means connecting said inner and outerrocker bars to said support for independent pivotal rocker bar movementabout an axis spaced from said support and between said fourth and fifthbogie wheels and for adjustable positioning of said fourth and fifthbogie wheels along the direction of intended travel.

3. A track suspension in accordance with claim 2 wherein said meanspivotally connecting said inner and outer rocker bars to said supportincludes an arm connected to said support for pivotal movement relativethereto and accompanying movement of said rocker bars and said fourthand fifth bogie wheels, and releasable means retaining said arm againstpivotal movement.

4. A track suspension in accordance with claim 2 wherein said meansconnecting said inner and outer rocker bars to said support includes anelastomeric mount resiliently restraining pivotal movement between saidsupport and said rocker bars.

5. A track suspension system including a frame, an arm including a firstend portion connected to said frame for pivotal movement thereofrelative to said frame and a second portion adjustable relative to saidfirst portion to vary the length of said arm, means releasablyrestraining pivotal movement of said arm relative to said frame, innerand outer rocker bars adjacently spaced relative to each othertransversely of the direction of intended travel, aligned pivot meansconnecting said rocker bars to said arm, and first and second innerbogie wheels connected to said inner bar on opposite sides of said pivotmeans and first and second outer bogie wheels connected to said outerbar on opposite sides of said pivot means.

6. A track suspension comprising a support, inner and outer front bogiewheels in adjacently spaced relation to each other transversely of thedirection of intended travel, means connecting each of said inner andouter front bogie wheels to said support for pivotal movement about anaxis transverse to the direction of intended travel, second inner andouter bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel, third inner and outerbogie wheels in adjacently spaced relation to each other transversely ofthe direction of intended travel, means including an outer leaf springpivotally connected intermediate the ends thereof to said support andrespectively connected at opposite ends to said second and third outerbogie wheels and an inner leaf spring pivotally connected intermediatethe ends thereof to said support and respectively connected at theopposite ends thereof to said second and third inner bogie wheels foraffording independent vertical movement of each of said second and thirdouter and inner bogie wheels, fourth inner and outer bogie wheels inadjacently spaced relation to each other transversely of the directionof intended travel, fifth inner and outer bogie wheels in adjacentlyspaced relation to each other transversely of the direction of intendedtravel, an outer rocker bar connected to said outer fourth and fifthbogie wheels, an inner rocker bar connected to said inner fourth andfifth bogie wheels, and means connecting said inner and outer rockerbars to said support for independent pivotal rocker bar movement aboutan axis spaced from said support and between said fourth and fifth bogiewheels.

7. A track suspension in accordance with claim 6 and further includingmeans foradjustable positioning of said fourth and fifth bogie wheelsalong the direction of intended travel. r

1. A track suspension comprising a support having, on each side thereof,an intermediate portion, front inner and outer bogie wheels, meansseparately mounting each of said front inner and outer bogie wheels fromsaid support forwardly of said intermediate portion in adjacently spacedrelation to each other transversely of the direction of intendeD travelfor resilient pivotal movement about an axis transverse to the directionof intended travel and spaced from the center of said front inner andouter bogie wheels, second inner and outer bogie wheels, third inner andouter bogie wheels, means including a common member extending from saidintermediate support portion for mounting said second and thrid innerbogie wheels in spaced relation to each other in the direction ofintended travel and for independent vertical movement, means includinganother common member extending from said intermediate support portionfor mounting said second and third outer bogie wheels in spaced relationto each other in the direction of intended travel and with said secondand third outer bogie wheels being respectively located in adjacentlyspaced relation to said second and third inner bogie wheels transverselyof the direction of intended travel and for independent verticalmovement of said second and third outer bogie wheels relative to eachother and to said second and third inner bogie wheels, fourth inner andouter bogie wheels, fifth inner and outer bogie wheels, and meansmounting said fourth and fifth inner and outer bogie wheels from saidsupport rearwardly of said intermediate portion with said fourth innerand outer bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel and with said fifthinner and outer bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel and for common pivotalmovement of said outer fourth and fifth bogie wheels and common pivotalmovement of said inner fourth and fifth bogie wheels independently ofsaid outer fourth and fifth bogie wheels and about an axis spaced fromsaid support.
 2. A track suspension comprising a support, inner andouter front bogie wheels in adjacently spaced relation to each othertransversely of the direction of intended travel, means separatelyconnecting each of said inner and outer front bogie wheels to saidsupport for limited resilient pivotal movement about an axis transverseto the direction of intended travel and spaced from the center of saidinner and outer front bogie wheels, second inner and outer bogie wheelsin adjacently spaced relation to each other transversely of thedirection of intended travel, third inner and outer bogie wheels inadjacently spaced relation to each other transversely of the directionof intended travel, means including an outer leaf spring pivotallyconnected intermediate the ends thereof to said support and respectivelyconnected at opposite ends to said second and third outer bogie wheelsand an inner leaf spring pivotally connected intermediate the endsthereof to said support and respectively connected at the opposite endsthereof to said second and third inner bogie wheels for affordingindependent vertical movement of each of said second and third outer andinner bogie wheels, fourth inner and outer bogie wheels in adjacentlyspaced relation to each other transversely of the direction of intendedtravel, fifth inner and outer bogie wheels in adjacently spaced relationto each other transversely of the direction of intended travel, an outerrocker bar connected to said outer fourth and fifth bogie wheels, aninner rocker bar connected to said inner fourth and fifth bogie wheels,and means connecting said inner and outer rocker bars to said supportfor independent pivotal rocker bar movement about an axis spaced fromsaid support and between said fourth and fifth bogie wheels and foradjustable positioning of said fourth and fifth bogie wheels along thedirection of intended travel.
 3. A track suspension in accordance withclaim 2 wherein said means pivotally connecting said inner and outerrocker bars to said support includes an arm connected to said supportfor pivotal movement relative thereto and accompanying movement of saidrocker bars and said fourth and fifth bogie wheels, and releasable meansretaining said arm against pivotAl movement.
 4. A track suspension inaccordance with claim 2 wherein said means connecting said inner andouter rocker bars to said support includes an elastomeric mountresiliently restraining pivotal movement between said support and saidrocker bars.
 5. A track suspension system including a frame, an armincluding a first end portion connected to said frame for pivotalmovement thereof relative to said frame and a second portion adjustablerelative to said first portion to vary the length of said arm, meansreleasably restraining pivotal movement of said arm relative to saidframe, inner and outer rocker bars adjacently spaced relative to eachother transversely of the direction of intended travel, aligned pivotmeans connecting said rocker bars to said arm, and first and secondinner bogie wheels connected to said inner bar on opposite sides of saidpivot means and first and second outer bogie wheels connected to saidouter bar on opposite sides of said pivot means.
 6. A track suspensioncomprising a support, inner and outer front bogie wheels in adjacentlyspaced relation to each other transversely of the direction of intendedtravel, means connecting each of said inner and outer front bogie wheelsto said support for pivotal movement about an axis transverse to thedirection of intended travel, second inner and outer bogie wheels inadjacently spaced relation to each other transversely of the directionof intended travel, third inner and outer bogie wheels in adjacentlyspaced relation to each other transversely of the direction of intendedtravel, means including an outer leaf spring pivotally connectedintermediate the ends thereof to said support and respectively connectedat opposite ends to said second and third outer bogie wheels and aninner leaf spring pivotally connected intermediate the ends thereof tosaid support and respectively connected at the opposite ends thereof tosaid second and third inner bogie wheels for affording independentvertical movement of each of said second and third outer and inner bogiewheels, fourth inner and outer bogie wheels in adjacently spacedrelation to each other transversely of the direction of intended travel,fifth inner and outer bogie wheels in adjacently spaced relation to eachother transversely of the direction of intended travel, an outer rockerbar connected to said outer fourth and fifth bogie wheels, an innerrocker bar connected to said inner fourth and fifth bogie wheels, andmeans connecting said inner and outer rocker bars to said support forindependent pivotal rocker bar movement about an axis spaced from saidsupport and between said fourth and fifth bogie wheels.
 7. A tracksuspension in accordance with claim 6 and further including means foradjustable positioning of said fourth and fifth bogie wheels along thedirection of intended travel.